The objective of this lab was to obtain a pure sample of methyl nitrobenzoate. This was done by performing a crystallization, vacuum filtration, and a recrystallization. Nitration is a commonly used reaction that involves an additional reaction that results in a resonance-stabilized intermediate that is later deprotonated to regenerate an aromatic ring. Because of methyl benzoate’s substituent, the nitro group is added in the meta position. The procedure included combining sulfuric acid, methyl benzoate, nitric acid, suction filtration, and purification through recrystallization. The recrystallized substance was then used to take the melting point determining how pure the crystals were. The reaction of methyl benzoate and nitric acid formed …show more content…
Loss of product occurred due to multiple transfers between glassware and during both vacuum filtrations. During the first filtration, the mother liquor was cloudy signifying that crystals had gotten under the filter paper and were lost. Washing the crystals with methanol made the mother liquor even cloudier meaning that the methanol was warm enough to dissolve the desired product and impurities (337). The crystals formed after the recrystallisation were a bright yellow color due to the possible reaction of the methyl benzoate with the sulfuric acid. Once they were rinsed with methanol, the yellow color disappeared. Due to the loss of color, and therefore byproducts, it can be assumed the product was relatively pure. Due to the high sensitivity of the nitric acid, and how cautious one must be while using this acid, the process took much longer, and more steps had to be taken after the vacuum filtration to ensure all the acid was no longer in the product. The melting point of the crystals was 76.2-76.9°C, as compared to the accepted value of 78°C. The slight melting point depression revealed a slight
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Lastly, product was GC traced to obtain the percentage of product and starting material within final product. Observations: Mixture turned yellow as sulfuric acid was added. During reflux condensation, sodium bromide dissolved and brown layer formed on top of solution as it boiled. Brown layer was alkyl bromide while clear, bottom layer was inorganic salts. After simple distillation, product was clear and colorless.
No precipitation was observed, which was also the same result when Na2CO3 was added to the unknown solution. Last but not least, a few drop of NaOH were added to the unknown solution, which resulted in the formation of precipitate. Now that the type of the cation in the solution was identified, it was time to clean up. First the test tube consisting of the unknown solution and precipitation was poured into a waste bucket. Afterwards, the wash bottles were returned to the rightful
To drive the reaction to the amide product, the reaction was performed at 300 ˚C to evaporate the water product, which is an application of Le Chatelier’s principle. Second, the aromatic nitro group was reduced to an amine using sodium dithionite. The reaction is given in Figure 1. Figure 1: Synthesis of luminol from 3-nitrophthalic acid and hydrazine. To verify the synthesis of luminol, the product was mixed with an oxidant (diluted bleach) and was inspected for a blue glow.
Once cool to touch the squeeze out all the tea bags carefully without tearing them apart. Using a separatory funnel extract three times with 15.0ml of dichloromethane gently rocking bath and forth the funnel venting the funnel often each time. Carefully decant into a pre-weighed 125ml flask and add the drying agent-calcium chloride pellets- and the organic layer was evaporated off in a warm water bath. Using aluminum foil as support around the mouth of the flask place test tube in the flask and heat the flask on a hot plate whilst adding water into the tube without letting it boil. Once the caffeine forms crystals around the test tube scrape off all the sublimed product and weigh the dried product 0.1grams of caffeine and had a melting point range of 175-230
Nevertheless, the latter is not used in this experiment since it is very reactive and extremely flammable. On the contrary, NaBH4 is relatively mild and it can be used with protic solvents. In this manner, 1.507 grs of the ketone 9-fluorenone were mixed with 30.0 ml of 95% ethanol in a 125 ml Erlenmeyer flask. The bright yellow mixture was stirred during 7 minutes until all the components were dissolved.
A mixture of 0.25 g of camphor (1.64 mmol), 1.5 mL of methanol, and 0.25 g of sodium borohydride (6.60 mmol, NaBH4) was boiled for 2 minutes. Moreover, the addition of 10 mL of ice deionized water resulted in a white solid after the organic solution was vacuum filtered. The organic solid was dissolved in 10 mL of dichloromethane (CH2Cl2) and small amounts of anhydrous sodium sulfate (NaSO4) to dry. The organic solution was decanted and evaporated for melting point (203.3-203.8 °C), NMR, and IR spectroscopy. Product formation and heats of formation (borneol = -1.203675E6 kJ/mol, isoborneol = -1.203687E6 kJ/mol) were analyzed.
Abstract: The goals of this experiment were to observe the changes in melting points across different compounds as well as the factors that affect melting point accuracy, which are impurities and amount of compound. The experiment begins by comparing the effectiveness in obtaining the recovery of a solid from a mixture between gravity and vacuum filtration. Which vacuum filtration had 11% loss while gravity had only a 7% loss. It was determined that pure benzoic acid had a melting range of 122.9-124.4 oC while impure benzoic acid had a melting range of 83.4-86.3 oC. The unknown compound 1 was determined to be palmitic acid through mixed melting point theory. Introduction:
The solution was warmed to 65oC with constant stirring on the magnetic stirrer till the solid was completely dissolved. Stirring was stopped and 0.4g of charcoal was then added to the solution. After which the solution was transferred to a Buchner funnel with a moist filter paper and the clear filtrate was collected via suction filtration. The residue was washed with warm solution of 10.035g of KI and 15ml of deionized water. 200ml of water was then added to the filtrate in a 500ml beaker with constant stirring.
Additionally, I compared IR spectra I obtained to official IR spectra for para-bromoaniline and 4-bromoacetanilide and they had the same important peaks. Between the two weeks, the reaction time was not very different and was about 15 minutes. The combination of data from TLC, IR, and melting point were able to help me asses the identity of my unknown product, and this the importance of characterization in
Lance Feig CH 128L Experiment Report Purpose The purpose of this lab was to synthesize methyl benzoate from benzoic acid and methanol through Fischer esterification. The identity of the product was verified through IR, GC, and 1H-NMR analysis, where the experimental readings were compared to known readings of methyl benzoate. Furthermore, a percent yield of the product was calculated.
In Experiment One we will be recrystallizing Benzoic Acid from water. In Experiment Two we will be recrystallizing Benzoic Acid using a solvent pair made up of Methanol and Water. The Seven step process of recrystallization consists of adding a solid organic substance into a solvent, then dissolving the chosen solute, decolorizing the solution, filtering solids, then recrystallize the solute by slowly cooling
That caused a new initial reading of NaOH on the burette (see Table1 & 2). The drops were caused because the burette was not tightened enough at the bottom to avoid it from being hard to release the basic solution for titrating the acid. The volume of the acid used for each titration was 25ml. The volume of the solution was then calculated by subtracting the initial volume from the final volume. We then calculated the average volume at each temperature.